Use of an extract from the leaves of Olea Europea as an antiradical

ABSTRACT

The use of an extract from the leaves of Olea Europea as an antiradical. Preferably, the extract is added to a preparation wherein the concentration of the extract does not exceed 0.5% by weight. The extract can be used both for preparing cosmetic products, such as cosmetic creams--particularly sun protection creams--and for preparing alimentary products--particularly dietetic products.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention concerns the use of an extract from the leaves ofOlea Europea (commonly called olive tree), as an antiradical,particularly in the cosmetic and alimentary fields.

2. Prior Art

The use of antioxidant substances, apt to prevent the forming of freeradicals, is rather widespread both in the alimentary and in thecosmetic fields.

In the alimentary field, the oxidizing action is what causes the food todeteriorate. It is hence frequent to add into foods antiradicals foralimentary use, such as acetylsalicylic acid and its esters, or1-ascorbic acid, which develop an antioxidant action.

In the cosmetic field, the antiradicalic substances are above all usedfor sun protection creams. In fact, the ultraviolet irradiation causesthe forming of free radicals which determine a sort of skin ageing and,after a prolonged exposure, may even lead to damages of neoplasticnature.

The extract from the leaves of Olea Europea, already known since quite along time, consists of an extremely complex mixture of organiccomponents: most of them have not yet been identified. Among thecomponents which have been identified, the main ones are oleoceuropeineand verbacoside. These two bitter glucosides are cited in literatureand, precisely, in the "Gazzetta Chimica Italiaina" (1960--Vol. 90, page1449) by L. Panizzi, M. L. Scarpati and E. G. Oriente, and in the"Journal of Food Science" (1993--Vol. 58, page 347) by M. Brenes, M. C.Duran and A. Garrido. Particularly oleoeuropeine is known as anantimicrobic substance, as resulting from the "Journal of AppliedBacteriology" (1970--Vol. 33, page 72; and 1972--Vol. 35, page 59) by B.Juven and Y. Hems.

It has now been found that the extract from the leaves of Olea Europea,which contains more than 7% of oleoeuropeine, has considerablepreserving properties. Such properties derive, not only from the knownantimicrobic action cited heretofore, but also from a considerableantiradicalic action--never evidenced up-to-date and, as a matter offact, even unexpected--which said extract has been found to develop.

SUMMARY OF THE INVENTION

The present invention has been conceived on the basis of said principleand actually concerns the use of an extract from the leaves of OleaEuropea as an antiradical.

Said antiradicalic action provides great advantages in the preparing ofcosmetics or foods.

In the cosmetic field, said extract finds its ideal use especially insun protection creams.

In the alimentary field, said extract is mainly used for preparingdietetic products.

Preferably, said extract is added to the cosmetic or alimentarypreparation in a concentration not exceeding 0.5% by weight.

The extract is prepared by dipping the leaves into water, and subjectingthe infusion to ultrasounds, so as to accelerate the extraction. Thisallows to obtain an extract containing at least 7% by weight ofoleoeuropeine. It is deemed that the antiradicalic action is partlyproduced by oleoeuropeine and partly by other substances synergisticallyacting therewith.

The extract thus obtained is added to the cosmetic or alimentarypreparation in a concentration not exceeding 0.5% by weight, and thenmixed therewith in any known manner.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In the cosmetic field, the action of the extract according to thepresent invention develops in the cosmetic product to which it is added,as well as on the tissues on which said product is applied. It isparticularly helpful in various types of cosmetic creams, and even morehelpful in the case of sun protection creams. Such products bring theextract in contact with the skin and, in the case of certainpreparations, they cause it to penetrate into the inner skin layers. Inall such cases, the active substances contained in the extract from theleaves of Olea Europea stop the forming, in the tissues, of the freeradicals determined by the action of ultraviolet irradiation--whether itbe of natural origin, or artificially produced--so as to protect theskin from a premature ageing and from any possible phenomena of theneoplastic type. Moreover, as mentioned above, said extract also actsonto the components of the cosmetic preparation, preserving it fromdecay due to radicalic oxidation and considerably lengthening its life.As can be easily understood, this type of action is particularlyappreciated and effective in the case of sun protection creams, whichare used in conditions of highly strong UV rays, whereby the forming offree radicals is very likely to occur.

In the alimentary field, the extract is used--according to theinvention--to delay the deterioration of the most perishable foodstuffs,for example long-life fruit juices or other soft drinks, jams and tinnedfruits and vegetables, sacked meats and sausages, and particularly, forthe preparing of dietetic products.

According to the present invention, the use in the alimentary field ispossible in that the extract contains sugars and agliconic derivatives,all of which are edible. Also in this case it is not necessary to exceeda concentration of 0.5% by weight, seen that the extract develops asynergistic action with the antircadicalic substances usually soluble inthe lipids, such as tocopherols. It is however advisable to proportioneach time the concentration according to the particular food beingpreserved. The antiradicalic action develops both directly andindirectly, through a protective action on the tocopherols.

Since the antiradicalic action is mostly developed by the agliconiccomponents, it is totally independent from the presence of enzymes. Itmay, on the contrary, develop both on the hydrosoluble and on theliposoluble substances, seen that aglicone is liposoluble: this allowsto use the extract according to the present invention also in thehot-prepared alimentary products. The water-solubility of the extract ofOlea Europea is remarkably higher than the effective dose; though beingvery low in the lipids, the solubility is however already sufficient togive an adequate protection to the alimentary substances also in thelipidic phase.

The present invention will now be described in further detail, withreference to an experimental test there(of, reported by mere way ofnon-limiting example.

EXPERIMENTAL TEST

The antiradicalic properties of the extract from the leaves of OleaEuropea have been verified through the test, proposed by Chaboun et al.,in BBA (1990--Vol. 1042, page 324).

Said test is based on the fact that; copper is a reactive radical whichproduces peroxidation. If lipoproteins are treated with copper, thepolyunsaturated fatty acids contained therein are considerably removed.

Two plasma samples were incubated, respectively containing 3 and 0.3mg/l of extract from the leaves of Olea Europea, and copper sulphate wasadded thereto in order to produce their peroxidation. The treatment withcopper sulphate was also carried out on a plasma sample containing nosuch extract: 80% of the eicosapentanoic acid, 80% of the docosaesanoicacid, 80% of the linolenic acid and 50% of the arachidonic acid,disappeared from this last sample. Whereas, in the two plasma samplestreated with the extract according to the invention, the concentrationof said fatty acids remained unvaried: this proves that theantiradicalic action of the extract from the leaves of Olea Europea isvery strong already at low concentrations.

What is claimed is:
 1. A method of preventing the formation of freeradicals in human skin, comprising applying to human skin an antiradicaleffective amount of an aqueous extract from the leaves of Olea Europeain a cosmetologically acceptable excipient, said extract containing atleast 7% by weight of oleoeuropeine, and the concentration of saidextract not exceeding 0.5% by weight.
 2. A method as claimed in claim 1,wherein said excipient is a cosmetic cream.